摘要
Cu-12.7(wt)%Al合金从900℃高温淬至365℃～500℃温度范围等温不同时间(30秒至15分钟)的试样中形成了大量树枝状的γ_2相沉淀粒子。应用配有X线能谱仪(XEDS)和电子能量损失谱仪(EELS)的分析电子显微镜(JEOL JEM-2000FX型)对上还试样研究,结果表明:这些γ_2相粒子具有富铝的“核心”,长大到粒子线度大于约800nm后以不稳定方式生长成“花朵”状。生长过程中伴随着溶质元素Al由基体向γ_2相内的富集。而且在γ_2相粒子内部呈现出Spinodal分解组织的形貌特征,表明γ_2粒子内形成了化学成分调幅。EELS分析表明试样含氧。
A Cu-Al alloy containing 12.7 (wt)% Cu was heated at 900°C for 2 hours follwed by iso-thermal holding between 365℃ and 500℃ for various durations. Rosette shaped gamma-2 phasewas formed during the isothermal treatments. Investigations on the morphology, fine structureand local chemical composition of the gamma-2 phase particles in the samples have been carriedout using an analytical electron microscope JEOL JEM-2000FX with XEDS and EELS. The result showed that the gamma-2 phase formed with Al enriched kernel and dendriticgrowth took place aftet the particle dimension was over about 800 nm. Spinodal decompositionwithin the gamma-2 particles has been observed and discussed.
基金
国家自然科学基金
关键词
铜铝合金
固态相变
电镜
XEDS
EELS
Analytical electron microscopy
X-ray energy dispersive spectroscopy
electron diffraction
phase transformation
copper-aluminium alloy
